Upright extracton cleaning machine with handle mounting

ABSTRACT

A portable surface cleaning apparatus including a base module for movement along a surface, an upright handle pivotally attached to the base module, a liquid dispensing system including a fluid supply chamber in the form of a bladder for holding a supply of cleaning fluid, a fluid recovery system including a tank on the base module having a fluid recovery chamber for holding recovered fluid and housing the flexible bladder, wherein the recovery chamber is in fluid communication with the fluid supply chamber and the pressure in the flexible bladder is equalized with the pressure in the tank as the cleaning fluid is dispensed from the supply chamber and the dirty liquid is collected in the recovery chamber. The base module includes upper and lower housing portions and the upright handle is pivotably mounted to the base module through at least one bearing for rotatable reception in the housing.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional application of U.S. patentapplication Ser. No. 09/575,929, filed May 23, 2000, which is adivisional application of U.S. patent application Ser. No. 09/112,527,filed Jul. 8, 1998, now U.S. Pat. No. 6,167,587, issued Jan. 2, 2001,which claims the benefit of U.S. Provisional Application Ser. No.60/075,924, filed on Feb. 25, 1998, and U.S. Provisional ApplicationSer. No. 60/052,021, filed on Jul. 9, 1997.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to an extraction cleaning machine. In oneof its aspects, the invention relates to an upright extraction cleaningmachine with a bearing for pivotally mounting a handle to a base.

[0004] 2. Description of the Related Art

[0005] Upright extraction cleaning machines have been used for removingdirt from surfaces such as carpeting, upholstery, drapes and the like.The known extraction cleaning machines can be in the form of acanister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase etal. or an upright unit as disclosed in U.S. Pat. No. 5,500,977 toMcAllise et al. and U.S. Pat. No. 4,559,665 to Fitzwater.

[0006] Current upright extraction cleaning machines can be made easierto use by limiting the weight and number of components, such as fluidstorage tanks, on the pivoting handle of the upright cleaning machine.Reducing the weight that a user must support as the handle is tiltedrearwardly can also lower the center of gravity for the machine, whichresults in a better feel to the user.

SUMMARY OF THE INVENTION

[0007] According to the invention, a portable surface cleaning apparatuscomprises a base module for movement along a surface and having a rearportion, an upright handle pivotally attached to the rear portion of thebase module, a liquid dispensing system and a fluid recovery system. Thebase module includes an upper housing portion and a lower housingportion. An upright handle is pivotally mounted to the rear portion ofthe base module through at least one bearing for pivotal reception inthe housing. According to the invention, a socket is formed between theupper and lower housing portions for rotatably receiving the bearing.Preferably, the bearing is formed integral with the lower portion of theupright handle. Desirably, the socket is formed by arcuate surfaces inmated edges of the upper and lower housing portions. The lower portionof the upright handle includes diverging arms, each including a bearing.Each bearing is formed integral with the lower portion of the uprighthandle. Typically, wheels are mounted to an axle which are receivedwithin the bearings for rotationally mounting the wheels to the handle.

[0008] Further according to the invention, a portable surface cleaningapparatus has a base module comprising a base housing having an upperhousing portion and a lower housing portion which have arcuate surfacesthat between them define a socket. An upright has depending armsspanning the base housing and having inner and outer sides, with theinner sides being adjacent the base housing. The inner sides of the armshave bearings which are rotatably received in the socket defined by thearcuate surfaces of the upper and lower housing portions for pivotallymounting the handle to the base housing.

[0009] Preferably, the bearings are formed integrally with the arms. Inone embodiment, the arcuate surfaces are formed by sidewalls of theupper and lower housing portions. Each bearing has an axis about whichthe handle pivots with respect to the base housing, an axle is mountedto each of the bearings and is coaxial with respect to the axis of thebearings and a wheel is rotatably mounted to each of the axles.

[0010] In a preferred embodiment, each bearing has a circumferentialslot in which the arcuate surfaces are received. Further, the bearingshave a relatively large diameter relative to the axles.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the drawings:

[0012]FIG. 1 is a perspective view of the extraction cleaning machineaccording to the invention;

[0013]FIG. 2 is an exploded view of a base module of the extractioncleaning machine shown in FIG. 1;

[0014]FIG. 3 is an exploded view of a base module and tank assembly ofthe extraction cleaning machine of FIG. 1;

[0015]FIG. 4 is an exploded view of a handle assembly and portions ofthe base module for the extraction cleaning machine of FIG. 1;

[0016]FIG. 5 is a partial sectional side view of the foot module of theextraction cleaning machine of FIG. 1;

[0017]FIG. 5A is an exploded view of a floating brush assembly for theextraction cleaning machine of FIG. 1;

[0018]FIG. 5B is a perspective view of an alternative brush assembly forthe extraction cleaning machine of FIG. 1;

[0019]FIG. 6 is a partial sectional side view of the extraction cleaningmachine of FIG. 1 with the handle assembly in a tilted position;

[0020]FIG. 7 is a side sectional view of the pump and pump primingassembly of the extraction cleaning machine of FIG. 1 with a plunger ina first position;

[0021]FIG. 8 is a side sectional view of the pump and pump primingassembly of the extraction cleaning machine of FIG. 1 with a plunger ina second position;

[0022]FIG. 9 is a partial perspective view of the belt access doorassembly of the extraction cleaning machine of FIG. 1;

[0023]FIG. 10 is a partial sectional view of the auto-mix valve of theextraction cleaning machine of FIG. 1 with a valve stem in a firstposition;

[0024]FIG. 11 is a partial view of the auto-mix valve of the extractioncleaning machine of FIG. 1 with a valve stem in a second position;

[0025]FIG. 12 is a partial side sectional view of a diverter valve withthe valve plate shown in a first position and in phantom for a secondposition for the extraction cleaning machine of FIG. 1;

[0026]FIG. 13 is a partial side view of the valve assembly of FIG. 12with the valve plate in the second position;

[0027]FIG. 14 is a sectional view of the air/water separator lid alongline 14-14 of FIG. 3;

[0028]FIG. 14A is a partial side view of a closure plate in threepositions relative an air exit from the air/water separator lid of FIGS.13 and 14;

[0029]FIG. 14B is a partial sectional view taken along lines 14B-14B ofFIG. 14;

[0030]FIG. 15 is a sectional view of the air/water separator lid alongline 15-15 of FIG. 14;

[0031]FIG. 16 is a partial sectional view of the tank assembly andhandle assembly of the extraction cleaning machine shown in FIG. 1;

[0032]FIG. 17 is a fluid flow diagram for the extraction cleaningmachine of FIG. 1;

[0033]FIG. 18 is an exploded view of the in-line heater of theextraction cleaning machine of FIG. 1;

[0034]FIG. 19 is a top view of the fluid flow indicator of theextraction cleaning machine of FIG. 1;

[0035]FIG. 20 is a side sectional view of the fluid flow indicator ofFIG. 19;

[0036]FIG. 21 is a bottom perspective view of a drain plug of the basemodule and tank assembly of FIG. 3; and

[0037]FIG. 22 is a top perspective view of the drain plug of the basemodule and tank assembly of FIG. 3 and illustrated in FIG. 22.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038] Referring now to the drawings and to FIG. 1 in particular, anupright extraction cleaning machine 12 according to the invention isshown. The machine 12 is a portable surface cleaning apparatus includinga base module 14 adapted to roll across a surface to be cleaned and anupright handle assembly 16 pivotably mounted to a rear portion of thebase module 14.

[0039] As best shown in FIGS. 1-3, the base module 14 includes a lowerhousing portion 15 and an upper housing portion 17, which togetherdefine an interior for housing components and a well 730 for receiving atank assembly 50. Further, a well 732 in the upper housing portion 17receives a detergent supply tank 870, as best shown in FIG. 3. The upperhousing portion 17 receives a transparent facing 19 for defining a firstworking air conduit 704 and a suction nozzle 34, which is disposed at afront portion of the base module 14 adjacent the surface being cleanedfor recovering fluid therefrom. The handle assembly 16 has a closed loopgrip 18 provided at the uppermost portion thereof and a combination hoseand cord wrap 20 that is adapted to support an accessory hose 22 and aelectrical cord (not shown) when either is not in use. A latch assembly21 is pivotably mounted to the rear portion of the base module 14adjacent the rotational union of the handle assembly 16 therewith forreleasably locking the handle assembly 16 in its upright position.

[0040] As shown in FIG. 2, the base module 14 houses a drive motor 196that is connected to a source of electricity by the electrical cord. Amotor compartment 500 within the base module 14 is a clamshell-shapedhousing for holding a motor assembly in place and preventing rotationthereof. The clamshell motor compartment 500 includes an upper half 502and a lower half 504. The upper half 502 is removable from the lowerhalf 504, which is integral to the extraction cleaner base module 14.Thus, a bottom wall of the lower half 504 is the bottom surface of theextraction cleaner base module 14. An arm 651 extends upwardly from themotor housing 500 in the base module 14 to support the flow indicator650, which is mounted to an upper end thereof. An opening 653 in theupper housing portion 17 receives the flow indicator 650 when thatportion is mounted to the lower housing portion 15.

[0041] The motor compartment 500 includes a large circular impeller fanhousing 510 and a smaller motor housing 512, further having a generallyT-shaped cross section. The impeller fan housing 510 surrounds an innerhousing 41 defining a vacuum source 40, which is created preferably byan impeller (not shown) disposed within the housing 41. The housing 41includes a large aperture 516 for mounting a vacuum intake duct 530,which is sealed to the aperture 516 by a gasket 520. The vacuum intakeduct 530 connects the vacuum source 40 to an air/water separationchamber 750 (shown in FIGS. 3, 14, 14A, 14B and 15) in a lid 700 on thetank assembly 50, as well as the suction nozzle 34 on the front portionof the base module 14 and a suction nozzle (not shown) on a distal endof the accessory hose 22. The smaller end 512 includes a small aperture524 for receiving therethrough a motor drive shaft 198. A stretch belt204 is received on the motor drive shaft 198 outside of the clamshellmotor compartment 500. Further, an upper surface 520 of the motorcompartment 500 supports and secures an accessory hose intake duct 540partially defining a second working air conduit 706 (as shown best inFIGS. 12-14), which connects the suction nozzle on the distal end of theaccessory hose 22 to the vacuum source 40.

[0042] The drive shaft 198 of the drive motor 196 is connected to aninterim drive shaft 200 of a solution pump 202 by the stretch belt 204,which in turn, is connected to a rotatably mounted agitation brush 206by a timing belt 208, as best illustrated in FIGS. 5 and 6. On theopposite side of the motor 196, the motor drive shaft 198 supports theimpeller (not shown) within the impeller housing 41, which provides thevacuum source 40 and is mounted inside the housing 510 of the motorcompartment 500. With this configuration, a single drive motor 196 isadapted to provide driving force for the impeller, the solution pump202, and the agitation brush 206.

[0043] As best seen in FIGS. 2, 5, 5A, and 6, the rotatably mountedagitation brush 206 is adapted for floor-responsive adjustment by afloating brush assembly 400 mounted within an agitation brush housing 26disposed within a forward portion of the base module 14. The floatingmovement of the agitation brush 206 is a horizontally oriented arcuatepath for reciprocation toward and outward of the agitation brush housing26. Ends 452 of an agitation brush shaft 206 are received in bearings454, which in turn, are press fit into inwardly extending bosses 456 toprovide a pair of opposed articulating arm members 458. Alternatively,stub shafts (not shown) can extend from the arm members 458 and the ends452 can be replaced with bearings similar to 454 for rotationalinstallation of the brush 206 on the arm members 458.

[0044] Each arm member 458 comprises a back plate 460 with a pivot pin462 provided at the rear of the plate 460. In addition, a laterallyextending belt guard 466 is preferably integrally formed with thearticulating arm 458. The belt guard 466, which extends laterallyinwardly enough to cover the timing belt 208, minimizes the lodging ofthreads and other foreign material in the timing belt 208 and protectsthe carpet or other surface positioned below the base assembly 14 fromthe rotating belt 208.

[0045] As best shown in FIGS. 5-6, 9, the timing belt 208 is reevedthrough a pulley 216 mounted at one end of the brush 206 and a pulley222 on the interim drive shaft 200 of the pump 202, which includes aseparate pulley 220 through which is reeved the stretch belt 204, which,in turn, extends around the drive shaft 198 of the motor 196. As bestshown in FIGS. 7 and 9, the radius of the pulley 220 is larger than theradius of the pulley 222. Further, the pulley 220 has a convex crosssection of its periphery, whereby it is adapted to receive the smoothstretch belt 204, while the pulley 222 has a toothed perimeter adaptedfor registration with the teeth in the timing belt 208.

[0046] The pivot pins 462 of the arm member 458 are rotatably supportedsecured in a bearing (not shown) mount integrally formed with aninternal wall of the agitation brush housing 26. Further, the pivot pins462 are held in the bearing by a support 478 on the non-belt side of thebase module 14 and the an arm 258 of the second belt access door 252 onthe belt side of the base module, as best shown in FIG. 5A. Both the arm258 and support 478 are secured to the agitation brush housing 26 by aconventional fastener (not shown) inserted through an aperture in eachpart. The arm members 458 are preferably limited in their downwardmovement relative to the agitation brush housing 26 by the length of thetiming belt 208 as well as the engagement of the brush guards 466 withthe arm 258 and the support 478. As the floating brush assembly 400extends further and further downwardly, the belt 208 will stretch andresist further downward movement. Eventually, the brush guards 466 oneach arm 458 will contact respectively the arm 258 and the support 478,which prevents any further downward movement.

[0047] With this floating agitation brush assembly 400, the cleaningmachine 12 according to the invention can almost instantaneously adaptto varying carpet naps or other inconsistencies on the surface beingcleaned. The arm members 458 also allow the rotating brush 206 to dropbelow the normal floor plane, as shown in FIG. 6, to, for example,provide contact with a bare floor.

[0048] As an alternative to the floating, rotatably mounted agitationbrush 206, a floating strip agitation brush 224 could be incorporatedinto the cleaning machine 12, as seen in FIG. 5B. In this embodiment,the strip brush 224 comprises a linear brush portion 492 with bristles494 extending downwardly therefrom, and a pair of integrally molded arms496 having pivot pins 502, which can mount to the arm members 458 inplace of the pivot pins 462 supporting the agitation brush 206. Withthis structure, the strip brush 224 can move vertically in response tochanges to the carpet nap or other inconsistencies in the floor beingcleaned.

[0049] As shown in FIGS. 2, 5 and 6, an elevator assembly 410 comprisesa central support member 412 having at one end an L-shaped actuating arm418, and at another end, the ramped surface 414 on a forward arm 404opposed by a guide 416. Between the guide 416 and the ramped surface 414is mounted a spring assembly 406, which biases the assembly 410 rearwardtoward the handle assembly 16. The spring assembly 406 includes a spring436; a stop 426, which is attached to the base module 14 and throughwhich the forward arm 404 travels; and a flange 428, which is integralwith the forward arm 404. The spring 436 is held between the flange 428and stop 426, and biases the assembly 410 rearward relative the stop 426through force on the flange 428.

[0050] The arm 418 extends from within the base module 14 where it ismounted, through an aperture 402, towards the handle assembly 16. Theactuating arm 418 is forced horizontally forward when the rotatablymounted handle 16 on the base module 14 is put in the upright position,which forces an upper portion 422 of the actuating arm 418 in ahorizontal and forward direction. More specifically, as shown in FIG. 5,a curved surface 424 on the handle assembly 16 strikes a rounded distalend 420 of the L-shaped actuating arm 418 when the handle assembly 16 isput in its storage or non-use position. When the handle assembly 16 ispivoted rearwardly for use, as shown in FIG. 6, the curved surface 424shifts rearwardly and the spring-biased elevator assembly 410 follows,with end 420 riding the curved surface 424, until the elevator assembly410 reaches a rearward, rest position.

[0051] Thus, forward movement of the actuating arm 418 forces thesupport member 410 and ramped surface 414 forward, wherein the rampedsurface 414 contacts the underside of the brush guards 466 on each arm458, thereby raising the floating brush assembly 400 as the elevatorassembly 410 moves from a rearward position to a forward position in thebase module 14. That is, as the ramped surface 414 moves towards thefront of the base module 14, the agitation brush assembly 400 slowlyrises as the brush guards 466 ride the ramped surfaces 414. Such aconstruction eliminates the need for a manual arm for lowering andraising the agitation brush assembly 400 for storage or use of theaccessory hose 22, thereby eliminating risks of damage to the brushassembly and protecting the carpet from the agitation brush assembly 400resting thereon. When the handle 16 is moved to the in-use position, thespring assembly biases the elevator assembly to its normal, rearwardposition.

[0052] As seen best in FIGS. 1 and 4, the base module 14 is supported atthe rear portion thereof by a pair of opposed rear wheels 552. Thehandle assembly 16 includes a U-shaped lower portion 560 having opposedarms 562 and 564 including cylindrical bearings 578 for mounting thehandle assembly 16 to the base module 14 and supporting axles 554 on acommon axis for rotatably mounting the wheels 552 to the extractioncleaner base module 14. More particularly, the handle assembly 16 tapersfrom its wide, lower portion 560 to a thinner handle portion 570, havinga thin handgrip portion 572, including the closed loop grip 18 at itsuppermost end, by which the user moves the extraction cleaner. Thebearing 578 include a central circumferential groove 576 for receivingarcuate portions 588, 589 of the base module 14 whereby rotation of thehandle assembly 16 is facilitated.

[0053] The handle assembly 16 further comprises a front portion 580 anda rear portion 582 defining a substantially hollow interior supported bymultiple ribs 558. Mounts 584, disposed radially on the interior of thefront and rear portions 580 and 582 support an in-line heater 54, aswill be described in detail below. The substantially flat front portion580 is secured to the mated rear portion 582 by conventional fasteners,such as screws. The rear portion 582 further includes the combinedaccessory hose and electrical cord mount 20.

[0054] Returning to the lower portion 560, the arms 562, 564 compriseportions of both the front portion 580 and the rear portion 582. Whenthe assembly 16 is secured together, these arms 562, 564 pivot about thebearing 578 integrally formed with the arms 562, 564. The bearings 578,in turn, receive axles 554, on each side, respectively, for mountingwheels 552. The axles 554 extend through the wheels 552, apertures 586through the rear portion 582 of the lower arms 562, 564, and thebearings 578 integrally formed with the arms 562, 564. The axles 554,556 are secured by large diameter axle mounting clips 594, disposed,when installed, adjacent the bearings 578 and within the base module 14.A side edge 598 of the extraction cleaner base module 14 includes anarcuate surface 588 to accommodate the handle bearings 578 secured oninside portions of each arm 562, 564 of the rear portion 582. As shownin FIG. 4, the bearings 578 have a diameter that is relatively largewhen compared to the axles 554.

[0055] Once the handle assembly 16 is mounted to each base module 14,with the axles 554 secured by the mounting clips 594, the extractioncleaner upper housing portion 17 is secured to the lower housing portion15. The upper housing portion 17 also has an arcuate surface 589 formedin a side thereof for accommodating and securing the integral bearings578 of the arms 562, 564. More specifically, the arcuate surfaces 588,589 of the side walls of the housings 15, 17 are received in the centralcircumferential groove 576 formed in the circumference of each integralbearing 578. Thus, when the base module 14 is formed of the housings 15,17, the bearings 578 of the arms 562 are secured therebetween such thatthey can only rotate between an upright, stored position and an in-useposition and the wheels are mounted to axles 554,556 received throughapertures in the bearings 578 and secured by mounting clips 594.

[0056] The concentric wheel axle and handle pivot transfers all theforce on the handle assembly 16 to the wheels 552 to keep downward forceon the suction nozzle 34 constant. Further, the tank assembly 50, asshown in FIG. 3, center of gravity is close to the wheel center so thatchanging tank volume does not alter the downward force on the suctionnozzle 34 and allows the weight of the tank assembly 50 to be carried onthe wheels 552 fairly evenly. Also, the handle assembly 16 supports verylittle weight and therefore keeps the weight that the user feels throughthe handle assembly 16 to a minimum. This creates an upright extractioncleaning machine 12 that is easy to use and less tiring for theoperator.

[0057] The handle assembly 16 is releasably locked against rotation fromits upright position by a latch assembly 21, which is pivotably mountedto the rear portion of the base module 14 adjacent the rotational unionof lower leg 564. The latch assembly 21 includes an upright lowerportion which is pivotally mounted to the base module 14 at a rearcorner thereof and an upper portion which extends upwardly andrearwardly of the lower portion. A molded-in spring arm extendsrearwardly from the lower portion of the latch assembly 21 and bearsagainst a rear portion of the base module 14 to bias the lower portionforwardly and against the rear portion of the lower leg 564. The upperend of the lower portion of the latch assembly 21 forms a horizontallatching surface which bears against the rear portion of the lower leg564 and engages projections thereon to lock the handle in the uprightposition in a conventional fashion. Thus, as the handle assembly 16 ispivoted upright, the rear portion of the lower leg 564 rides along thehorizontal latching surface until the edge catches the projection on therear portion of the lower leg 564, at which point the handle assembly 16is locked upwardly. To release the latch assembly 21, the user pushesthe step downwardly and against the bias of the molded-in spring torelease the horizontal latching surface from the projection. Thelatching mechanism is conventional and forms no part of the invention ofthis application. Any conventional latching mechanism can be used withthe handle and base module in the invention.

[0058] The tank assembly 50 is removably supported on the rear of thebase module 14. An air/water separator lid 700 seals the top of the tankassembly 50, which includes a valve mechanism 80 on a bottom portion forcontrolling the flow of cleaning solution fluid from the fluid supplychamber 49. The base module 14 includes a valve seat 88 complementary tothe valve mechanism 80, and the bottom portion of the tank assembly 50and the valve seat 88 are substantially complementary to one another sothat the upwardly extending valve seat 88 is substantially surrounded byand received in the bottom of the tank assembly, as will be describedfurther below.

[0059] The lid 700 is secured to the tank assembly 50 by a rotatablehandle 790, as best shown in FIG. 16, which can be moved between astorage position, in which the tank 50 is sealed by the lid 700 and thehandle 790 is disposed rearwardly horizontal (as shown in solid lines);a transport position, in which the tank 50 is sealed and the handle 790extends vertically upward (shown in phantom lines) for ease in carryingby the user; and a service position, in which the lid 700 can be removedfrom the tank assembly 50 and the handle 790 is disposed forwardly at anacute angle relative the lid (shown in dashed lines). The U-shaped tankhandle 790 rotates about a pivot 792 projecting from a side of the lid700. The pivot 792 is received in a bushing 794 disposed centrally in acircular mounting portion 796 at the ends of the handle 790. An arcuatewall 798 extending transversely from the mounting portion 796, integraltherewith, and having an opening 788 surrounds the bushing 794. When thehandle 790 is rotated about the pivot on the lid, an inside surface 784of the wall 798 engages a tab 786 extending transversely from an upperlip 782 of the tank assembly 50 for locking the lid 700 to the tankassembly. The surface 784 of the wall 798 engages the tab 786 when thehandle 790 is in either the storage or transport position. When in theservice position, the tab 786 is aligned with the opening 788 in thewall 798, whereupon the lid 700 can be removed from the tank assembly50.

[0060] As best shown in FIGS. 3, 14, 15, a flexible bladder 120, whichis used as a clean water reservoir, is mounted inside a rigid tankassembly 50. Thus, the tank assembly 50 is divided into two fluidchambers by the bladder 120: a fluid supply chamber 49, comprising theinterior of the bladder 120, and a fluid recovery chamber 48, comprisingthe volume between the flexible bladder 120 and the rigid walls of thetank housing 46. The bladder 120 is molded from a pliable thermoplasticmaterial and is collapsible when empty to accommodate recovered fluid inthe volume between the bladder 120 and the tank housing 46. Initially,the bladder 120 is full of water or cleaning solution and occupies thevast majority of the volume within the tank housing 46. As the usersprays the cleaning solution onto the surface to be cleaned, the volumeof fluid in the bladder 120 is reduced corresponding to the volume ofsolution sprayed on the surface. During suction, recovered dirt andwater are received in the tank housing 46 in the volume between thebladder 120 and the tank housing 46. The volume available in the bladder120 due to application of the cleaning solution is made available torecovered fluid by the pressure of the recovered fluid collapsing thebladder 120, thereby forcing air out of the bladder 120. Becauserecovery of the used cleaning solution is always less than 100% of thesolution applied, there will always be ample room inside the tankhousing 46 once the cleaning solution has been applied to the surface.

[0061] The bladder 120 is disposed within the tank assembly 50 between abottom surface 860 of the rigid tank housing 46 and a snap-in baffleplate 800, which will be explained in further detail below. An aperture824 in the baffle plate 800 has a diameter approximately matching thatof a small diameter end 125 of a funnel-shaped filling spout 124 of thebladder 120. Further, an upstanding collar 828 surrounds the aperture824. A cylindrical shroud 770, as best shown in FIG. 17, is mounted onthe inside of the air/water separator lid 700 and extends downwardlytherefrom to capture the filling spout 124. Thus, the increasingdiameter outside surface of the funnel-shaped filling spout 124 isretained in the aperture 824 and supported by the collar 828, therebyholding the flexible bladder 120 in an upright position in the tankhousing 46 between the bottom surface 860 and the baffle plate 800therein. As space between the upstanding collar 828 and the downwardlyextending shroud 770 defines a fluid passageway between the fluid supplychamber 49 and the recovery chamber 48, whereby the fluid supply chamber49 and the recovery chamber 48 maintain the same pressure, negative orotherwise.

[0062] The flexible bladder 120 includes an outlet 130 disposed in alower corner of the flexible bladder 120. The outlet 130 is mated withan outlet aperture 862, as best viewed in FIG. 16, in the bottom surface860 of the rigid outer shell for supplying fluid to a fluid applicationsystem 950 and securing the bladder 120 to the rigid bottom surface 860of the tank housing 46.

[0063] The funnel-shaped filling spout 124 of the bladder 120facilitates filling the bladder 120 and equalizing air pressure betweenthe fluid supply chamber 49 and recovery chamber 48. The filling spout124 is always open, so as to vent air from the bladder 120 as itcollapses in volume and the usable volume within the rigid outer wallsof the tank housing 46 expands in volume. Further, the open fillingspout 124 ensures that both chambers 48, 49 are at substantially thesame atmospheric pressure, which is preferably negative relative tostandard atmospheric pressure because of the communication of the vacuumsource 40 to the tank assembly 50 via the air/water separator lid 700,as will be explained further below. The volume of the bladder 120 ispreferably one gallon.

[0064] As best shown in FIG. 17, the valve mechanism 80 is providedwithin the outlet aperture 862 through the bottom surface 860 of thetank housing 46 and the aligned outlet 130 in the bladder 120 forcontrolling the flow of cleaning solution fluid from the fluid supplychamber 49. The valve mechanism 80 comprises a valve member (not shown)mounted within the aligned aperture 862 and outlet 130, which togetherare selectively covered by the valve member to enable or prevent theflow of fluid to the fluid application system 950.

[0065] The base module 14 includes a valve seat 88, shown best in FIG.17, that has a fluid reservoir 90 adapted to receive fluid through thefluid aperture 862 and conduct this fluid to one end of the conduit 140,the other end being mounted to a clean water inlet 332 of a mixing valveassembly 310. The bottom wall 860 of the tank housing 46 and the valveseat 88 are substantially complementary to one another so that theupwardly extending valve seat 88 is substantially surrounded by andreceived in the bottom wall 860. A projection 94 is provided in thefluid reservoir 90 and is adapted to contact a head of a shaft of thevalve member (not shown). A spring received on the shaft of the valvemember is adapted to bias the valve member into the closed positionthereby preventing the flow of fluid through the fluid apertures. Whenthe tank housing 46 is seated on the base module 14, the head of thevalve member contacts the projection 94 and deflects the valve upwardlythereby permitting the flow of fluid around the valve, through the fluidapertures into the fluid reservoir 90 of the valve seat 88, and to thefluid application system 950. A gasket 81 seals the junction between thevalve mechanism 80 and the seat 88. When the tank housing 46 is removedfrom the base module 14, the projection 94 is removed from contact withthe head 96 of valve member. Therefore, the spring biases the valvedownwardly into the closed position thereby preventing the flow of fluidthrough the fluid aperture 862 to the fluid application system 950.

[0066] The fluid application system 950 conducts fluid from the fluidsupply chamber 49 to fluid dispensing nozzles 100, which are mounted inthe brush housing 26 of the base module 14, and a fluid dispensingnozzle (not shown), which is mounted on an accessory cleaning tool (notshown), as best illustrated in FIG. 17. From the fluid supply chamber49, clean water is conducted through conduit 140 to an inlet 332 to themixing valve assembly 310, which also includes a detergent inlet 336that is fluidly connected to a detergent supply tank 870 by a conduit314. Mixed detergent and clean water form a solution that exits themixing valve assembly 310 via an outlet 340, which is fluidly connectedby a conduit 142 to a pump priming system 280 disposed adjacent the pump202. An inlet port 282 for the pump priming system 280 is connected tothe conduit 142, and pressurized fluid is expelled from the pump 202through a pump outlet port 283, which is fluidly connected via a conduit146 to a T-connector 150. The T-connector 150 supplies pressurized fluidto both the accessory tool (not shown) and the heater 54 via conduits148, 138, respectively. The conduit 148 includes a grip valve 132 bywhich the user can manually displace a valve member, thereby enablingthe flow of non-heated, pressurized fluid to the spray tip on theaccessory tool.

[0067] The conduit 138 includes a trigger valve 134 having adisplaceable valve member actuable by a trigger assembly 430, as bestshown in FIG. 4, for selectively supplying the in-line heater 54 withpressurized cleaning solution. The trigger assembly 430 includes aswitch 432 mounted conveniently within the closed loop grip 18 of theupright handle assembly 16, through which the user can depress theswitch for actuating a manual link 434 for displacing the valve memberin the trigger valve 134, thereby allowing fluid to flow to the inletport 72 of the in-line heater 54.

[0068] Heated while passing through the heater 54, the fluid exits thein-line heater 54 via an outlet port 74, which is fluidly connected viaa conduit 136 to an inlet 652 for a flow indicator 650. An outlet 654for the flow indicator is fluidly connected to a T-connector 156 via aconduit 134. The T-connector 156 supplies fluid dispensing nozzles 100,which are mounted in the brush housing 26 of the base module 14, andsupplied with heating cleaning solution via conduits 126, 128.

[0069] A detergent supply tank 870, as best illustrated in FIG. 3, isreceived within a well formed in the upper housing 19 of the base module14. The supply tank 870 includes a top surface 872 shaped complimentaryto the exterior of the upper housing 17. A bottom surface 874 of thesupply tank 870, as best shown in FIG. 17, includes an aperture 876surrounded by a threaded spout 878, which receives a mated threaded cap880 having a valve mechanism 882 therethrough. The valve mechanism 882will not be described here as its structure and function mimics thatvalve mechanism 80 described above for the tank assembly 50, as it tooseats on a projection 94 in a valve seat 318 for displacing the valvemechanism 882. The valve seat 318 of the mixing valve assembly 310includes a fluid reservoir 320 for receiving and conducting fluid to oneend of an L-shaped conduit 314, the other end being mounted to adetergent inlet 336 of the mixing valve assembly 310. The threaded cap880 also includes an air return conduit 890 mounted therethrough forequalizing the pressure inside the detergent supply tank 870 with theoutside atmosphere.

[0070] The mixing valve assembly 310 is positioned intermediate the tankassembly 50 and the solution pump 202. Preferably, the mixing valve 310is a variable mixing valve to accommodate differing mixtures ofdetergent and clean water. As seen in FIGS. 10, 11 and 17, the variablemixing valve 310 comprises a valve body 330 having a clean water inlet332 that is fluidly connected to the fluid supply chamber 49 and adetergent inlet 336 that is fluidly connected to a detergent supply tank870 by the valve seat 318 and, via the fluid reservoir 320, the L-shapedconduit 314. The mixed solution outlet 340 is also formed on the valvebody 330 and is adapted to conduct the clean water and detergentmixture, i.e., the cleaning solution, from the mixing valve 310 to afluidly connected pump priming system 280 adjacent the inlet of the pump202.

[0071] The valve assembly 310 includes an end cap 344 mounting a coaxialplunger 350 in a central body portion 346. The end cap 344 partiallyreceives a thread 372 of a knob 374 such that the plunger 350 can beraised or lowered in the valve body 346 when the knob 374 is turned.

[0072] The plunger 350 includes an annular groove 356 formed in a distalend 276 thereof. The groove 356 is received within an O-ring 358. Thedistal end 276 and O-ring 358 are adapted to create a fluid seal insidethe circular valve body 346 when the plunger 50 is in its lowermostportion, as shown in FIG. 11, and define a mixing chamber 360 when theplunger 350 is raised from its lowermost position, as shown in FIG. 10.

[0073] The distal end 276 of the plunger 350 further includes a taperedgroove 364, which is tapered so that the groove has a greatercross-sectional area immediately adjacent the head end 276 than it doesa distance spaced upwardly therefrom. The tapered groove is positionedin the detergent inlet 336 opening to control the flow of detergenttherethrough. That is, the tapered groove 364 accommodates varying flowrates of detergent from the detergent supply 870, through the conduit318, and through the detergent inlet 336 into the valve body 346. Thelower the plunger 350 is seated in the inlet 336, the less the area ofexposure of the tapered groove 364 in the valve body 346, therebylimiting the flow of detergent thereto.

[0074] The control knob 374 is mounted on an outside wall of the upperhousing of the extraction cleaner for controlling the water to detergentratio in the cleaning solution delivered to the fluid application system950. The control knob 374 is mounted adjacent the end cap 344 andincludes a thread 372 that is received in a groove 380 of the end cap344, so that turning the knob 374 lowers or raises the plunger 350 inthe valve body 346. In a first position shown in FIG. 10, with theplunger 350 extended upwardly from the valve body 346, the maximumcross-sectional area of the tapered groove 364 is exposed to define aninlet aperture 382 into the valve body 346. Therefore, the maximumamount of detergent will be drawn into the valve body 346 to mix withclean water supplied via inlet 332, and ultimately discharged to thepump assembly 280 and fluid dispensing nozzles 100. The other extremeposition of the plunger 350 lowers the tapered groove 364 from themixing chamber 360 completely so if there is no aperture 382 and thus nofluid flow communication between the detergent inlet 336 and the valvebody 346. Therefore, only water will be directed to the pump assembly280 and spray tips.

[0075] As should be evident, rotation of the threaded knob 374 willprovide an infinite number of detergent-to-water mixing ratios betweenthe two extremes described above. In the preferred embodiment, however,the housing adjacent the knob 374 is marked with three concentrationindicators: The first indicator is a water only or “rinse” position;second, a maximum detergent-to-water mixing ratio where the taperedgroove 364 is fully exposed in the valve body 346; or third, a standardmixing ratio approximately half way between the extremes describedpreviously. Of course, any variation of the indicated concentrationpositions can be employed by simply rotating the knob 374 to a positionbetween any two indicated positions. The extreme positions are definedby the shape of the length of the thread 372, which includes oppositeends defining a pair of extreme positions for limiting the rotation ofthe knob 374 relative the cap 344.

[0076] In use, the knob 374 is intended to be positioned at the standardmixing ratio position for the vast majority of cleaning operations. Whena high-traffic or heavily stained area is encountered, the knob 374 canbe rotated to the maximum detergent position. If a clean-water rinsingoperation is desired, then the knob 374 can be rotated to the water onlyposition.

[0077] As best illustrated in FIG. 17, the mix of detergent and water isdelivered via conduit 142 to the inlet port 282 for the pump primingsystem 280, which is disposed adjacent an inlet nose 288 of the pump202. Thus, in operation, the drive motor 196 is activated, therebyimparting rotation through the drive shaft 198 to the interim driveshaft 200, and the pump 202 is primed, as will be explained below.Rotation of the interim drive shaft 200 causes the pump 202 topressurize the fluid received from the fluid supply chamber 49, via themixing valve assembly 310 and priming assembly 280. Further, rotation ofthe interim drive shaft 200 causes the agitation brush 206 to rotate.Pressurized fluid flowing from a pump outlet port 283 is conducted tothe in-line heater 54, a flow indicator 650, and then a plurality ofconventional fluid dispensing nozzles 100 provided near the front of thebase module 14 adjacent the agitation brush 206. The pressurizedcleaning solution sprays down onto the surface to be cleaned in afan-shaped pattern extending substantially the entire width of the basemodule 14. A fluid outlet port 74 of the in-line heater 54 is alsofluidly connected to a conduit 144, which is integrated into theaccessory hose 22. Fluid flows through the conduit 144 to the accessoryhose cleaning tool (not shown) provided at the terminal end of the hose22. With this configuration, pressurized cleaning solution is availableon demand for both the accessory cleaning tool and the fluid dispensingnozzles 100.

[0078] Referring to FIGS. 2, 5 and 6, the drive shaft 198 of the drivemotor 196 is interconnected to the interim drive shaft 200 of thecentrifugal solution pump 202 by the stretch belt 204, which allows dry,high speed operation and operates as a clutch during brush roll-jamconditions. The interim pump shaft 200 is interconnected to therotatably mounted agitation brush 206 by the timing belt 208, whichallows a slower, high torque wet operation.

[0079] The interim pump drive shaft 200 functions as an interim driveproviding a step down from the drive shaft 198 to the stretch belt 204and the timing belt 208 to the agitation brush 206. Because of the stepdown structure, the drive motor 196 can be a high efficiency, high speedmotor (30,000 plus rpm), which is stepped down at the interim drive pumpshaft (approximately 12,000 rpm), and further stepped down at theagitation brush 206 (approximately 3,500 rpm).

[0080] The pump shaft 200 includes the pair of coaxial spaced-apartpulleys 220, 222, as best seen in FIGS. 2, 8-9, for receiving eachrespective belt 204, 208, with a radially extending baffle 218 disposedbetween the pulleys so that the inwardly disposed stretch belt 204 isinsulated from the wet environment in which the outwardly disposedtiming belt 208 operates to drive the agitation brush 206. A barriercoplanar with the radial baffle 218 insulates the environments from eachother as formed by the juncture of a pair of belt access doors 250, 252,as will be described below. The stretch belt 204 also functions as aclutch when the agitation brush 206 is jammed. Because the agitationbrush 206 is connected to the interim pump drive shaft, and the interimpump drive shaft 200 is connected to the motor drive shaft 198, theremust be some mechanism to provide relief to the motor 196 when theagitation brush 206 is jammed. This relief occurs at the drive shaft198, which will turn inside the stretch belt 204 without rotating thestretch belt 204 when the interim pump shaft 200 stalls due to anagitation brush 206 jam.

[0081] As best shown in FIGS. 5-9, the timing belt 208 is structurallywalled off from the stretch belt 204 by the barrier defined in part bythe first belt access door 250, second access door 252, and the baffle218. Removing the first belt access door 250 provides access to thetiming belt 208 connecting the pump drive shaft 202 and the agitationbrush 206. Access to the stretch belt 204 connecting the motor driveshaft 198 to the pump drive shaft 202 is provided only when the secondbelt access door 252, disposed within a brush housing 26, is removed. Asillustrated in FIG. 2, the first belt access door 250, having asubstantially L-shaped cross-section, includes a substantially verticalportion 266 and an angular, but substantially horizontal portion 264. Asbest shown in FIG. 9, the second belt access door 252 is rectangular,including an arcuate groove 254 in a front portion of a top surface 256and a transversely extending arm 258 in a rear portion of the topsurface. The arm 258 secures the second door 252 in place in the brushhousing 26 and supports the pivot pin 462 on the pivot arm 460 of thefloating brush assembly, as best shown in FIG. 5A.

[0082] More specifically, as shown in FIG. 2, the substantially verticalportion 266 of the first door 250 includes sides 240 that are receivedin a mated recess 242 surrounding an access aperture 236. Further, thefirst door 250 includes a depending flange 234 mounted to and spacedapart from a back portion of the door 250 and extending downwardlyparallel to the door 250 and further including an arcuate groove 244 ina lower end. Each side of the substantially horizontal portion 264includes a flexible tab 226 on each side that is received in arespective slot 228 disposed on the substantially horizontal face 222 ofthe upper housing 17 at each end of the access aperture 236 thatreceives the first belt access door 250. Thus, as the first belt accessdoor 250 is slid into place, the depending flange 234 extends behind theupper housing 17 defining the access aperture 236, the sides arereceived in grooves 242 in the upper housing 17 surrounding accessaperture 236, and the tabs 226 engage the slots 228 formed on thesubstantially horizontal portion 248 of the housing, whereby the firstaccess door 250 is secured in place. The first access door 250 can beremoved from the aperture 236 by flexing the tabs 226 inwardly torelease them from their receiving slots 228. As shown in FIG. 9, theinner depending flange 234, including groove 244, mates with theradially extending baffle 218 between the pulleys 220, 222 on the shaft200 and the arcuate groove 254 in the arm 258 of the second belt accessdoor 252 to separate the motor/pump stretch belt 204 from thepump/agitator timing belt 208.

[0083] The pump priming system 280 is disposed adjacent the pump inletnose 288, and draws from the fluid supply chamber 49 and the detergenttank 870. The fluid supply chamber 49 is under negative pressure becauseit is in fluid communication with the recovery chamber 48 and the vacuumsource. Once primed, the pump 202 draws solution from the mixing valveassembly 310, and delivers the mixture to a spray tip 100 or anaccessory tool 44 for spraying on the surface to be cleaned. When thepump 202 stops, the solution in the supply conduit is drawn into thelow-pressure fluid supply chamber 49 and away from the pump 202. Acentrifugal pump is incapable of developing sufficient pressure to primeitself by overcoming the negative tank pressure.

[0084] With reference to FIG. 7, a pump priming assembly 280 asdescribed herein overcomes this problem. The pump-priming assembly 280,includes a priming chamber 260 for flooding the inlet nose 288 of thepump 202, an inlet port 282 for the chamber 260 that is fluidlyconnected to the nose 288 of the pump 202, and a pump outlet port 283. Avacuum port 284 is fluidly connected to the vacuum source 40, or aportion of the recovery chamber 48 that is in fluid communication withthe vacuum source 40.

[0085] The pump-priming assembly 280 also includes a hollow valve body298 having a plunger chamber 286 and a valve chamber 292. A valvedopening 295 joins the valve chamber 292 and the priming chamber 260. Anoutlet opening 291 joins the valve chamber 292 and the plunger chamber286. Also, an aperture 294 is formed at an upper inside portion of thevalve body 298 to fluidly connect the valve body 298 and the outlet 284.An elongate buoyant plunger 290 having a top portion 297 at one end anda rubber umbrella valve 296 at the other is received for reciprocalmovement inside the valve body 298. More specifically, the umbrellavalve 296 reciprocates between the valved opening 295 and the outletopening 291 and within the valve chamber 292. Thus, the plunger chamber286 substantially houses the elongate plunger 290, while the valvechamber 292 houses the umbrella valve 296, which is coaxially attachedto the elongate plunger 290 for reciprocal axial movement therewith.

[0086] In operation, the pump 202 will be primed with fluid from thefluid supply chamber 49 by activating the pump 202 and the vacuum motor196, which will exert negative pressure on the vacuum outlet 284,thereby drawing any air out of the priming chamber 260 and plungerchamber 286, and further overcoming the negative pressure exerted on thefluid in the conduits 140, 142 connecting the fluid supply chamber 49 tothe pump 202. The air will be drawn through the valve body 298 into thevacuum impeller fan housing 510. Preferably, the weight and dimension ofthe plunger 290 is coordinated with the amount of negative air pressureapplied to the pump priming assembly 280 from the vacuum source 40 sothat the negative air pressure applied to the plunger chamber 286 isinsufficient by itself to draw the plunger 290 upwardly and seal theoutlet opening 291

[0087] As the vacuum motor operates to draw the air from the system,fluid fills the chamber 260 and enters the chambers 292, 286.Eventually, the fluid level will fill the valve chamber 292 and riseinside the plunger chamber 286, pushing the plunger 290 upwardly causingthe umbrella valve 296 to seal the outlet opening 291, therebypreventing water from rising further in the plunger chamber 286 andbeing sucked into the vacuum source 40. Because the pump nose 288 issubmersed at this point, water enters the pump 202 and primes it. As thepump 202 sucks water from the priming chamber 260, the plunger 290 isdrawn downward in the plunger chamber 286, and the umbrella valve 296descends therewith in the valve chamber 292 to activate a seal in theopposite direction, as the umbrella valve 296 seats in the valvedopening 295. The reverse seal prevents air from being sucked into thepriming chamber 260 from the fluidly connected chambers 292, 286. Thiscycle repeats each time a trigger 432 in the closed loop handle 18 isactivated or the unit is powered off and on again. Once the reverse sealhas been established, the chamber 260 should remain filled, the nose 288of the pump 202 flooded, and, thus, the pump 202 sufficiently primed fornormal operation.

[0088] From the pump 202, the pressurized fluid flows through a conduit146 to a T-connector 150 for supplying both floor nozzles 100 and anaccessory tool 44. The T-connector 150 includes outlets 152, 154 forsupplying both the in-line block heater 54, and a floor spray nozzle 64,or an accessory cleaning tool 44, respectively. Specifically, the firstoutlet 152 of the T-connector 150 is connected to fluid conduit 148 thatis adapted to supply non-heated and pressurized cleaning solution to aspray nozzle (not shown) on an accessory cleaning tool (not shown)mounted at the terminal end of the accessory hose 22. The second outlet154 is fluidly connected via a conduit 138 to the inline block heater54, shown best in FIG. 18.

[0089] The in-line block heater 54 receives pressurized cleaningsolution from the pump 202, via the T-connector 150, and further has aheating element 56 that is electrically connected to a source ofelectricity (not shown). As shown in FIG. 18, the heater 54 includes analuminum body 84 having an inlet port 72, an outlet port 74, a heatingelement 56 disposed within the aluminum body 84, and a serpentinechannel 78 disposed on a top face 76 of the block heater 54. A cover 79,via a gasket 70 seals the top face 76, and thus the channel 78, andfasteners 86. The heating elements 56 located in the aluminum body 84 ofthe block heater 54 uniformly heat the fluid as it passes through thechannel 78 across the block heater 54. The channel 78 includes an outletport 74 through which heated fluid exits the channel 78 to the conduit136. The heater 54 is mounted within the handle assembly 16 via shafts71 and plugs 73 to bosses (not shown) in the handle assembly 16.

[0090] The size of the aluminum body 84 and the heating elements 56 areselected to effectively deliver approximately 500 watts of power to theheating block 54 to heat the cleaning fluid in the serpentine channel 78to a temperature of about 150-180° during the dry cycle of the cleanerand apply that heated cleaning fluid during the wet cycle, as will bedescribed more completely below. Use of approximately 500 watts of powerfor the heater 54 leaves sufficient power from a convention 120 voltpower line for the vacuum motor, agitation brush and pump while heatingthe solution to the target temperature with a minimal warm-up time ofapproximately one minute. To enhance this process, hot tap water(defined as approximately 110-120° Fahrenheit) can be dispensed into thereservoir from a household tap. The solution that passes through thein-line block heater 54 is heated approximately 30° to 35° to reach atarget temperature of approximately 150° Fahrenheit. A thermostaticcontroller is preferably mounted to a face of the heater 54 to limit theblock temperature to 180° F. The solution that passes to the upholsteryattachments does not get the temperature boost. A non-heated solution ispreferred for upholstery, which is more sensitive to heat damage.

[0091] Powered by approximately 500 watts, the in-line block heater 54will boost the temperature of water 16° Fahrenheit on a continuous basisat 850 milliliters a minute. Since an approximately 30° temperatureincrease is desired, it is necessary to store heat energy in thealuminum body 84 of the in-line heater block 54 during the dry cycle anddeliver it to the solution during the wet cycle. The recommendedcleaning process with the extraction cleaning machine 12 describedherein is two wet strokes, defined as movement of the extractioncleaning machine 12 while cleaning solution is sprayed from the nozzles100 to the carpet being cleaned, followed by two dry strokes, defined ascleaning solution and dirt removal through the suction action of thesuction nozzle 34. There is thus an opportunity to effectively deliver1000 watts of heat energy to the solution by storing 500 watts duringthe dry cycle. Furthermore, a typical cleaning stroke is about 10seconds maximum, so the heat reservoir must have the capacity to store500 watts for approximately 20 seconds, which equals approximately10,000 Joules of energy.

[0092] The heating element 56 is embedded into the aluminum body 84,which is of ample mass to store the energy at some temperature below theboiling point of water (212° Fahrenheit). The larger the mass ofaluminum, the smaller the differential temperature needs to be to storethe required energy. On the other hand, the larger the mass, the longerthe initial heat-up period becomes. Thus, there is an optimal size ofaluminum block that is calculated based on a thermostat shut-off pointof 180° Fahrenheit. This block temperature keeps stagnant water fromboiling and also heats the solution that passes through the serpentinechannels 78 on the block face 76 to a temperature of approximately 150°Fahrenheit before leaving the in-line block heater 54 through outletport 74.

[0093] In operation, when the heater 54 is initially energizedelectrically, it heats to its thermostatically controlled shut-offtemperature in approximately one minute. A thermostat 92 is included ona lower face 108 of the body 84. During use, the cleaning solutionpasses through the heating channel 78 in the in-line block heater 54,drawing energy from the aluminum body 84 and from the heating element 56embedded therein adjacent the underside of the solution channel 78. Thealuminum body 84 cools somewhat during the 20 second cycle and reaches atemperature slightly below its starting temperature. During the drycycle, the aluminum body 84 is reheated to its previous temperature ofapproximately 180° Fahrenheit. The heated solution leaving the in-lineblock heater 54 is applied to the carpet after passing through theconduit 136 to the flow indicator 650, and the conduit 134 from theindicator 650 to the fluid dispensing nozzles 100, which are positionedbetween the agitation brush 206 and the suction nozzle 34.

[0094] The flow indicator 650 is placed in the fluid flow path toprovide a visible indication of fluid flow to the fluid dispensingnozzles 100. As shown in FIGS. 19 and 20, the flow indicator 650 ismounted to an upper end of the arm 651, which extends upwardly from themotor housing 500 in the base module 14. An opening 653 in the upperhousing portion 17 receives the flow indicator 650 when that portion ismounted to the lower housing portion 15. Alternatively, the flowindicator 650 can be mounted to the handle assembly 16 in a position tobe easily viewed by the operator. The flow indicator 650 comprises acircular body 660 having an inlet 652, outlet 654, and a clear lid 662having a threaded lip 670. As seen in FIG. 20, the indicator body 660preferably houses an impeller 664 superjacent a screen filter 666, bothof which are superjacent the fluid inlet 652 and the fluid outlet 654.The fluid inlet 652 is near the periphery of the body 660 and the outlet654 is disposed centrally. The lid 662 has threads 670 on the outside ofthe body 660.

[0095] The lid 662 is clear, preferably made from the transparentplastic, so that the user can see the fluid flowing into the indicator650 and rotating the impeller 664. Alternatively, one or more articles,such as a ball or disk can be mounted within the indicator body 660 andsubjacent the lid 662, whereby the operator can determine if there isfluid flow by movement of the article. Further, while a body 660mounting an impeller 664 is the preferred flow indicator, other suitableindicators include a float ball, spring plunger, or gravity plunger.

[0096] A float ball-type flow indicator can include a flow conduithaving a T-shaped portion having a transversely oriented tube extendingfrom a cylindrical body defining the fluid flow path. A ball or otherarticle can be mounted at the junction of the transverse tube andcylindrical body for reciprocation within the transverse tube. Whenfluid is flowing through the cylindrical body, the ball or article movesinto the transversely oriented tube, whereupon it is visible to theoperator and indicates proper fluid flow.

[0097] A spring plunger-type flow indicator can include a light springto bias a ball, plunger, or other article in a housing having a windowvisible to the operator. With fluid flowing through the housing, theball, plunger, or other article moves against the bias of the spring tobecome visible in the window, thereby indicating to the operator thatfluid is flowing properly. Alternatively, the ball, plunger, or otherarticle can always be partially visible, and include portionscorresponding to proper fluid flow, such as green for proper fluid flowand red for no fluid flow, whereby fluid flow causing movement of theball, plunger, or other article against the spring bias would change theportion of the ball, plunger, or other article visible to the operatorthrough the window, thereby indicating proper fluid flow.

[0098] A gravity plunger-type flow indicator can include a housinghaving a ball or other article mounted on a ramp adjacent a window. Asfluid flows through the housing, the ball or other article is forced upthe ramp, whereby it is visible to the operator to indicate proper fluidflow. Alternatively, like that for the spring plunger, a portion of theball or other article previously not visible through the window can bevisible when fluid flows through the housing to indicate to the operatorthat fluid flow is proper.

[0099] After pressurized fluid leaves the in-line heater 54, it entersthe inlet 652 of the flow indicator 650 under pressure, such that itcauses the impeller 664 to rotate in a clockwise direction as picturedin FIG. 20. The fluid rotates the impeller 664 until it reaches thecenter of the body 660, where it is forced through the screen filter 666and outlet 654 by the continuous flow of pressurized fluid into the flowindicator body 660.

[0100] The screen filter 666 prevents any debris from exiting the flowindicator 650. Any debris trapped by the screen filter 666 remainsvisible to the operator through the lid 662. The operator can simplyclean the flow indicator 650 by removing the threaded lid 662 andlifting the screen filter 666 from within the body 660 for cleaning. Thescreen filter 666 preferably includes apertures defined by the screen ofa diameter smaller than the diameter a passageway through the spraynozzle 64. This is of particular importance if the spray nozzle is noteasily serviceable by the operator or a service provider. Further, whenusing an in-line heater 54, a screen filter 666 is a precaution againstplugging the passageway through the spray nozzle 64 from scales formingin the heater 54.

[0101] After the cleaning solution has been applied to the surface to becleaned via the spray nozzle 64, or multiple spray nozzles 64, the usedcleaning solution and entrapped dirt are removed from the surface beingcleaned through the suction nozzle 34, which opens into the firstworking air conduit 704 extending along the top of the base module 14between the upper housing portion 17 and the transparent facing 19, asbest shown in FIGS. 2, 12 and 13. The first working air conduit 704terminates at a junction 740 with the second working air conduit 706,which is defined by passageway communicating the vacuum source 40 withthe suction nozzle (not shown) on the distal end of the accessory hose22. With this configuration, the drive motor 196 creates the vacuumsource 40 that is applied to the surface being cleaned through eitherworking air conduit 704, 706.

[0102] The terminal end of the accessory hose 22 is secured to a hosemounting 702 at a distal end of the accessory hose intake duct 540partially defining the second working air conduit 706, which extends, ina U-shape, to the junction 740 with the working air conduit 704, as bestseen in FIGS. 1 and 12. A flapper valve 114 pivots at the junction 740,disposed in the base module 14, to alternatively close the first workingair conduit 704, between the suction nozzle 34 and the air/waterseparator lid 700, and the second working air conduit 706 between thehose mounting 702 and the air/water separator lid 700, as best shown inFIGS. 12 and 14. The valve 114 seats on a gasket 113 about the junction740. When the user is cleaning floors, the flapper valve 114 is inposition to direct all of the working air generated by the vacuum source40 to the suction nozzle 34. However, when the user desires to use theaccessory hose 22, the flapper valve 114 is pivoted to an accessory hoseposition, as shown in phantom lines in FIG. 12. In this position, theflapper valve 114 seals the working air conduit 704 and connects theaccessory hose 22 to the vacuum source 40. Regardless of whether themachine is operating for on-the-floor cleaning or accessory hosecleaning, all of the dirt and water recovered are directed into therecovery chamber 48.

[0103] An over-center diverter valve assembly 110 including a movableflapper valve 114 in the junction 740 between working air conduits 704,706, and actuable by an actuator knob 180, on the extraction cleanerhousing controls the diversion between the conduits 704, 706. Morespecifically, the actuator knob 180 to flapper valve 114 linkageassembly, as shown best in FIGS. 12 and 13, includes an arm 160 attachedat an upper end to the flapper valve 114, which includes a transverselyextending support axle 162, and at a lower end to a cup-shaped bearing170 on the end of a piston 172. The support axle 162 is mounted forrotation in the junction 740 between the working air conduits 704, 706,whereupon the valve can pivot between two extreme positions, as shown inFIG. 12. At a lower end, the arm 160 ends in a transversely extendingleg 164, which moves relative the center of the actuator knob 180depending on the position of the actuator knob 180 when turned by theuser.

[0104] The actuator knob 180 includes a handle 184, and a pistonassembly 190 on a back face. The piston assembly 190 includes pistonhousing 176, piston 172, and a compression spring 174. The piston 172slides coaxially in the housing 176, and is biased upwardly by thespring 174 mounted therein. Specifically, the spring 174 biases thepiston 172 out of an opening 196 in a top portion of a tubular pistonhousing 176.

[0105] When the actuator knob 180 is turned by the user, the lower leg164 moves closer or farther from the knob rotation axis, therebyincreasing or decreasing the distance between the lower leg 164 and theaxis. As this distance increases, the spring-biased piston 172 forcesthe lower leg 164 upwardly. The arcuate path of the lower leg 164 as ittravels over the center of the knob axis rotation imparts rotation tothe flapper valve 114 about the fixed support axle 162. The rotation isin response to the changed distance of the mounting of the pistonassembly 190 from the actuator knob 180 rotation center. As it movesaway from the center, the piston 172 expands at an angle relative to thesupport axle 162. The lower leg 164 of the L-shaped arm 160 must rotatein the cup-shaped bearing 170 at the end of the piston 172 because theaxle 162 is fixed. Thus, the flapper valve 114 rotates in response tothe angle of the joint between the expanded piston 172 and the lower leg164 (not shown). Tabs formed on the back face of the knob 180 limit therotation of the knob so as to effectively define two positionscorrelating to the open conduit 704/closed conduit 706 position and theopen conduit 706/closed conduit 704 positions.

[0106] The diverter valve assembly 110 described above permits theupright extraction cleaner fluid dispensing mechanism to be used as apre-spray applicator. That is, by diverting the suction to the accessoryhose 22, and applying solution through the fluid dispensing nozzles 100adjacent the agitation brush 206, the upright extraction cleaner 12 canbe used to dispense fluid and agitate the carpet without having theapplied solution immediately extracted from the carpet through thesuction nozzle 34 adjacent the agitation brush 206 and fluid dispensingnozzles 100. Thus, the fluid application system 950 remains operableregardless of the position of the flapper valve 114.

[0107] As best seen in FIGS. 12-14, 14A and 14B, the working air conduit704 terminates at the junction 740 with the working air conduit 706. Thejunction 740 connects the selected conduit 704, 706 to a U-shaped inlet780 to the air/water separator lid 700, which is secured to the tankassembly 50 by the rotatable handle 790. Thus, from the U-shaped inlet780 to the air inlet 764, the air path entering the lid 700, as shown inFIG. 14, is substantially horizontal.

[0108] From the tank air inlet 764, the air/water/debris mixture isconducted into a center portion of a tank lid separation chamber 750,where the cross sectional area is greater than the flow conduits 704,706, junction 740, and inlets 780, 764 to slow down the velocity of theair stream for gravity separation of the air from the liquid, dirt anddebris. Because the lid 700 is formed of a transparent plastic material,the user can easily observe the dirt and water passing up through theintermediate flow conduit and the fluid level inside the tank assembly50.

[0109] The substantially rectangular chamber 750 is defined by atransparent lower portion 752 substantially surrounded on all sides by atransparent side wall integral with the underside of the air/waterseparation lid 700. The chamber 750 is further defined upwardly by atransparent face 756 of the lid 700. The air inlet opening 764 isdisposed adjacent an air outlet opening 776. The underside of the face756 further includes a circular downwardly extending shroud 770 adaptedto surround in part the open flexible bladder filling spout 124, whichis retained by the baffle plate 800 and positioned adjacent theseparation chamber 750.

[0110] The working air flow enters the hollow interior of the separationchamber 750 via the air and water inlet 764 and passes horizontallybeneath the transparent face 756 to a rear wall defining a firstdiverter baffle 755 at which it is redirected 180° forwardly through anopening 751 to a rectangular, extended outlet passage 757 formed in alower, intermediately disposed portion of the bottom wall 752 at whichit is again redirected 180° by a second diverter baffle 759 defined by afront wall disposed forward, transverse, and beneath the opening 751.The air flow then exits the separation chamber 750 through an inletoutlet 760, whose position is dictated by tank geometry, as thepreferred position is a “dead spot” in tank air flow to maximizeair/water separation. From here, the water is directed into the interiorof the tank between the 750 and the baffle 800, and away from theseparation chamber 750 to the air exit 762. It is significant that allair/water separation occurs above the baffle plate 800, thus minimizinginterference with the recovered water (i.e., no foaming) in the areadisposed below the baffle plate 800. This characteristic is necessitatedby the inclusion of a flexible bladder disposed in the tank recoverychamber.

[0111] In summary, air and water enters the inlet 764, from where it ischanneled to the air/water separation chamber 750 in which it strikesthe first diverter baffle 755, is redirected approximately 180° andthrough the opening 751 to the outlet passage 757, where it is againredirected approximately 180° by second diverter baffle 759, and thenpasses into the interior of the recovery chamber 48. The multiplechanges in direction as well as the expansion in volume in theseparation chamber 750 facilitate the separation of water and debrisfrom the air. As best seen in FIG. 14, the air, free of water anddebris, exits the tank via rectangular outlet 762, and traverses ahorizontal conduit 774 to a vertical exit conduit 776, which is disposedadjacent the horizontal inlet 780 leading air into the separation lid700 via air inlet opening 764. Thus, the air inlet 780 and air exitconduit 776 are vertically adjacent. The air exit conduit 776 feeds thevacuum intake duct 530, which is connected to the vacuum source 40, asbest seen in FIGS. 2 and 15.

[0112] As best shown in FIGS. 3, a fluid containment baffle 800 ismounted inside the hollow interior of the tank assembly 50 immediatelybelow the separation lid 700, and is intended to prevent the excessivesloshing of the recovered dirt and liquid and also contain any foamgenerated inside the tank assembly 50. The planar baffle 800 comprises aflat body 810 mated to snap fit within the tank housing 46. Further,apertures 820 are formed through the plate 800 for receiving therecovered fluid into the recovery chamber 48 of the tank assembly 50. Acircular aperture 826 retains the bladder filling spout 124 in positionby preventing it from floating upwardly in the tank and further lockingthe bladder in place while giving it mechanical support.

[0113] The baffle plate 800 is snapped into place by retainers 830 thatare received on tabs 836 formed on the interior of tank housing 46 tosecure the baffle plate 800 in the tank assembly 50. The apertures arecentrally mounted in the baffle plate 800 to prevent air movement, whilefacilitating fluid and debris deposits, into a lower portion of tankassembly 50 so that the recovered fluid remains undisturbed. Further,the baffle plate 800 is closed at the edges to prevent sloshing of therecovered fluid into an upper portion of the tank assembly 50 duringmovement of the cleaning machine 12.

[0114] As shown best in FIGS. 14 and 14A, a float assembly 900 extendsthrough the baffle plate 800 for moving an integral door across the exitport of the tank to prevent recovered solution from entering the tankexhaust in an overfill condition. As best shown in FIG. 3, theflag-shaped float assembly 900 comprises a buoyant base 902 and aclosure plate 904 interconnected to one another by a support plate 906.The closure plate 904 is dimensioned to fully seal the air exit 762 tothe tank to prevent recovered solution from entering the tank exhaust inan overfill condition, as illustrated in phantom lines in FIG. 14A. Theclosure plate 904 further includes a pair of triangular projections 905extending transversely from a substantially vertical front face. Thefront face engages the wall 768 defining the air exit 762 from the tank,and the projections 905 cam along that wall 768 to prevent premature andpartial closing of the exit 762 as the plate 904 is drawn against theexit by the suction therethrough.

[0115] The float assembly 900 is limited primarily to vertical movementwith respect to the tank assembly 50, with the closure plate 904positioned above the fluid containment baffle 800 and the buoyant base902 positioned below the baffle 800. A narrow slot 920 is provided in afront portion of the baffle 800 through which the support plate 906 ofthe float extends. Further, a housing 910 secured to the interior of thetank housing 46 guides the buoyant base, and thus the float assembly900, in a vertical direction. In the assembled position, the closureplate 904 is positioned above the baffle 800 and the buoyant base 902 ispositioned below the baffle 800.

[0116] As the recovered fluid within the tank assembly 50 rises, thefloat assembly 900 will also rise until, eventually, the closure plate904 nears the tank exhaust exit opening, at which point the closureplate 904 is sufficiently drawn against the exit 762 opening by thesuction from the vacuum motor to close the airflow therethrough. Asdiscussed above and illustrated in FIG. 14A, the triangular projection905 extending from the front face 907 ensure the closure plate is notdrawn against the exit 762 prematurely, which would result in a partialclosure of the opening. Rather, the projections 905 ride the housingdefining the opening until drawn into total closure of the exit 762.Once this happens, the pitch of the operating vacuum changessufficiently to warn the user that the fluid recovery chamber 48 is fulland must be emptied.

[0117] As best shown in FIG. 3, a drain plug 850 seals an aperturethrough a wall in a lower portion of the rigid housing 46 of the tankassembly 50 through which recovered fluid can be removed without tippingthe tank assembly 50, and also through which the tank assembly 50 can becleaned by flow-through rinsing. More specifically, a rounded wall ofthe rigid tank housing 46 includes the drain plug 850 mounted in anaperture 854. A bottom portion of the aperture 854 is substantiallyplanar with a bottom wall 860 of the tank housing 46. Thus, anyrecovered fluid will flow through the aperture 854 when the drain plug850 is removed therefrom. Further, the tank assembly 50 can be cleanedwithout having to tip the tank assembly 50 since the drain plug 850 canbe removed for flow-through rinsing. This feature is particularlyimportant because the flexible bladder 120 defining the fluid supplychamber 49 remains in place while the recovered fluid is drained fromthe recovery chamber 48. The drain plug 850 eases cleaning of both theinterior of the rigid housing 46 and the exterior of the flexiblebladder 120.

[0118] As best shown in FIGS. 21 and 22, the drain plug 850 comprises aknob 851 extending through a circular washer 856 which mounts tworesilient legs 853. The resilient legs 853 are located diametrically ona lower face of the washer 856 and comprise, on an outer face of eachleg 853, an upper ridged protrusion 857 and a lower ridged protrusion858. The lower ridged protrusion 857 is rounded so that it forms adetent mechanism with the opening in the tank wall. The upper ridgedprotrusion 857 has a slanted outer surface so that the legs areresiliently deflected as the drain plug is installed into the aperture854, and has a sharp return inner surface so that the return innersurface will bear against the inner surface of the wall of the tankhousing as the drain plug 850 is pulled outwardly of the tank. Thus, thedrain plug is easily installed into the aperture 854, but is retainedtherein by the inner surface when the plug is removed from the aperture854 for draining the tank. In the normal, closed position of the drainplug 850, the lower face of the washer 856 abuts the rear wall of thetank housing 46. The drain plug further has a pair of retaining flanges859 which fit behind the wall of the tank adjacent the aperture 854. Tothis end the aperture has indented slots to receive the flanges 859. TheTo drain fluid through the aperture 854, the drain plug 850 is rotated aquarter turn counterclockwise and pulled toward the rear of the uprightextraction cleaning machine 12 a suitable distance such that the upperridged protrusion 857 of the resilient legs 853 moves past the rear wallof the tank housing 46 and the lower ridged protrusion 858 of theresilient legs 853 abuts the inner wall of the tank housing 46. Thediameter of the aperture 854 is less than the normal distance betweenthe resilient legs 853 so that the legs 853 are pressed inwardly andthereby prevent the drain plug 850 from separating from the tank housing46. The drain plug 850 is restored to its normal, closed position bypressing the drain plug 850 toward the front of the upright extractioncleaning machine 12 to cause the washer 856 to abut the rear of the tankhousing 46 and turning the drain plug 850 one-quarter turn clockwise.

[0119] In use, the operator removes the tank assembly 50 from the well36 in the base module 14, and further removes the lid 750 from the tankhousing 46 to expose the open filling spout 124 of the flexible bladder120, whereupon the bladder 120 can be filled with water from a sourcesuch as a household tap. Next, the user replaces the lid 750 and swingsthe handle 790 upwardly to seal the lid 750 to the tank housing 46,whereupon the tank assembly 50 can be carried to the well 36 of the basemodule 14 and replaced therein for use. Upon replacement, the valvemember 82 in the valve mechanism 80 mounted in the bottom surface 862 ofthe tank housing 46 is displaced by the projection 94 in the valve seat88, whereupon the clean water in the fluid supply chamber 49 is in fluidcommunication with the fluid application system 950. The detergentsupply tank 870 is removed from its well 884, and then its cap 880 isremoved so that the tank 870 can be filled with concentrated detergent.Once the supply tank 870 is filled and the cap 880 is replaced thereon,the supply tank 870 is replaced in its well 884, whereupon its valvemechanism 882 permits the flow of concentrated detergent through theconduit 318 to the mixing valve assembly 310.

[0120] The extraction cleaning machine 12 can then be powered byactivating an main power switch 534 disposed on the handle assembly 16,whereby the motor 196 is activated, and the vacuum source 40 for theworking air flow conduits 704, 708 are operable. Further, the heater 54is separately operable by a heater power switch 536 when the main powerswitch 534 is in the “on” position. The user then supplies pressurizedcleaning solution to the agitation brush 206 by depressing the switch432 in the closed loop grip 18, whereupon solution flows to and throughthe fluid dispensing nozzles 100. As the user applies cleaning fluid andagitates the surface being cleaned with the brush 206, the user pushesthe cleaning machine 12 forward and rearward, with the forward strokesbeing defined as wet cycles and the rearward strokes being defined asdry cycles. During the wet cycles, the cleaning solution is applied tothe surface via the fluid dispensing nozzles 100 and the agitation brush206 scrubs the subjacent surface. During the dry cycles, the suctionnozzle 34 removes applied solution, as well as dirt and debris, from thesurface being cleaned and carries it to the recovery chamber 49 via theworking air conduit 704.

[0121] The cleaning machine 12 can also be used as a pre-sprayapplicator and agitator by simply diverting the air from working airconduit 704 to the working air conduit 708, which connects the vacuumsource 40 to the accessory hose 22. In this use, the accessory hose 22functions solely as a bypass aperture for the working air supplied bythe vacuum source 40. Thus, fluid is applied via the fluid dispensingnozzles 100 and agitated into the surface being cleaned by the brush206, but there is no suction at the suction nozzle 34, and thus no drycycle. When the solution has been adequately applied and the surfaceadequately agitated, the user can divert suction back to the working airconduit 704, whereupon the applied solution and other debris can beremoved from the surface without application of solution, which iscontrolled by the user through trigger 432.

[0122] To use the accessory cleaning tool (not shown), the user divertsworking air flow from the conduit 704 to the conduit 708, whereupon theaccessory hose 22 is fluidly connected to the vacuum source 40.Furthermore, the user can apply pressurized cleaning fluid to thesurface to be cleaned by pressing the grip valve 132 on the accessorycleaning tool. In sum, cleaning solution can be applied by actuating thegrip valve 132 and removed via the suction nozzle (not shown) incommunication with the vacuum source 40 via the working conduit 708.Also, the accessory tool may further include an agitation brush drivenby an impeller that is driven by ambient air drawn through an aperturedistinct from the suction nozzle in the accessory tool, but towards thesame vacuum source 40.

[0123] Once the surfaces have been cleaned, or the recovery chamber 48has become filled and the float assembly 900 has blocked the air exit762 from the air/water separator lid 750, power to the cleaning machine12 is turned off and the tank assembly 50 is removed from the well inthe base module 14 and carried by its handle 790, which seals the lid750 to the tank housing 46, and carried to a point of disposal, such asa sink drain, whereupon the contents of the recovery chamber 48 can beemptied by removing the drain plug 850 from the aperture 854 throughwall 852. Once removed, the contents of the recovery chamber 48 flowthrough the aperture 854. Furthermore, the tank assembly 50 can berinsed with clean water, which also flows through the aperture 854 inthe wall 852 of the tank housing 46.

[0124] While particular embodiments of the invention have been shown, itwill be understood, of course, that the invention is not limited theretosince modifications may be made by those skilled in the art,particularly in light of the foregoing teachings. Reasonable variationand modification are possible within the scope of the foregoingdisclosure of the invention without departing from the spirit of theinvention.

What is claimed is:
 1. A portable surface cleaning apparatus,comprising: a base module for movement along a surface and comprising abase housing having a rear portion; the base housing including an upperhousing portion and a lower housing portion which have arcuate surfacesthat between them define a socket; an upright handle having dependingarms spanning the base housing, the arms having inner and outer sides,with the inner sides being adjacent the base housing, the inner sides ofthe arms having bearings which are rotatably received in the socketdefined by the arcuate surface of the upper and lower housing portions,for pivotally mounting the handle to the base housing; a fluid recoverysystem comprising: a tank having a fluid recovery chamber for holdingrecovered fluid; a suction nozzle associated with the base module; aworking air conduit extending between the recovery chamber and thesuction nozzle; a vacuum source in fluid communication with the recoverychamber for generating a flow of working air from the nozzle through theworking air conduit and through the recovery chamber to thereby drawdirty liquid from the surface to be cleaned through the nozzle andworking air conduit, and into the recovery chamber; and a liquiddispensing system comprising: a liquid dispensing nozzle associated withthe base module for applying liquid to a surface to be cleaned; a fluidsupply chamber for holding a predetermined amount of supply fluid; and afluid supply conduit fluidly connected to the fluid supply chamber andto the dispensing nozzle for supplying liquid to the dispensing nozzle.2. A portable surface cleaning apparatus according to claim 1 whereinthe bearings are formed integrally with the arms.
 3. A portable surfacecleaning apparatus according to claim 2 wherein the arcuate surfaces areformed by sidewalls of the upper and lower housing portions.
 4. Aportable surface cleaning apparatus according to claim 2 and furthercomprising: each bearing having an axis about which the handle pivotswith respect to the base housing; an axle mounted to each of thebearings and coaxial with respect to the axis of the bearings; and awheel rotatably mounted to each of the axles.
 5. A portable surfacecleaning apparatus according to claim 1 wherein the arcuate surfaces areformed by sidewalls of the upper and lower housing portions.
 6. Aportable surface cleaning apparatus according to claim 1 wherein eachbearing has a circumferential slot in which the arcuate surfaces arereceived.
 7. A portable surface cleaning apparatus according to claim 1wherein the bearings have a large diameter relative to the axles.
 8. Aportable surface cleaning apparatus, comprising: a base module formovement along a surface and comprising a housing having a rear portion;the housing including an upper housing portion and a lower housingportion; an upright handle pivotally attached to the rear portion of thebase module and including a lower portion having a bearing for rotatablereception in the housing; a fluid recovery system comprising: a tank onthe base module having a fluid recovery chamber for holding recoveredfluid; a suction nozzle associated with the base module; a working airconduit extending between the recovery chamber and the suction nozzle; avacuum source in fluid communication with the recovery chamber forgenerating a flow of working air from the nozzle through the working airconduit and through the recovery chamber to thereby draw dirty liquidfrom the surface to be cleaned through the nozzle and working airconduit, and into the recovery chamber; a liquid dispensing systemcomprising: a liquid dispensing nozzle associated with the base modulefor applying liquid to a surface to be cleaned; a fluid supply chamberfor holding a predetermined amount of supply fluid; a fluid supplyconduit fluidly connected to the fluid supply chamber and to thedispensing nozzle for supplying liquid to the dispensing nozzle; theimprovement comprising a socket formed between the upper and lowerhousing portions for rotatably receiving the bearing.